1. Field of the Invention
This invention is in the field of animal guards for drain pipes of the kind that prevents animal entry into an open pipe end but provides for free-flow of debris carrying effluents from the open pipe end.
2. Description of the Prior Art
This invention is an improvement over the guard shown in U.S. Pat. No. 3,118,469 entitled "Animal Guard for Tile Drain Pipe" issued to John O. Schliesser, father of the present inventor. In that patent, a guard is disclosed having a generally circular baffle member which is pivotably connected at an upper perimetral point inwardly from the open end of a field pipe and is free to pivot in an arcuate first direction towards the open end and towards the upper pipe surface to provide for substantially free-flow of effluents, which frequently carry debris, towards the open pipe end. A stop member is positioned in the pipe adjacent the baffle member on the side opposite the side facing the open end. The stop member has a pair of outwardly inclined leg portions which engage symmetrically disposed portions of the baffle member on either side of the pivotal point to prevent its pivoting in an arcuate second direction opposite to the first direction so that animal entry past the member is effectively prevented.
While the device of the aforementioned Schliesser Patent has worked satisfactorily in the field for a number of years, it has been found that the stop member, while effectively preventing pivoting of the baffle member to prevent animal entry, tends to collect debris on the outwardly angled depending arms thus blocking free-flow of the effluents, interfering with pivotal baffle member movement, and resulting in corrosion of the stop members due to the trapped debris and continued exposure to the moisture and impurities carried and retained by the debris.